Biomedical Sciences Program, Texas A&M University, College Station, TX, United States of America.
Department of Biology, Texas A&M University, College Station, TX, United States of America.
PeerJ. 2024 Jul 23;12:e17740. doi: 10.7717/peerj.17740. eCollection 2024.
Chromosomal fusions play an integral role in genome remodeling and karyotype evolution. Fusions that join a sex chromosome to an autosome are particularly abundant across the tree of life. However, previous models on the establishment of such fusions have not accounted for the physical structure of the chromosomes. We predict a fusion joining an autosome to the pseudoautosomal region (PAR) of a sex chromosome will not remain stable, and the fusion will switch from the X to the Y chromosome each generation due to recombination. We have produced a forward-time population genetic simulation to explore the outcomes of fusions to both the PAR and non-PAR of sex chromosomes. The model can simulate the fusion of an autosome containing a sexually antagonistic locus to either the PAR or non-PAR end of a sex chromosome. Our model is diploid, two-locus, and biallelic. Our results show a clear pattern where fusions to the non-PAR are favored in the presence of sexual antagonism, whereas fusions to the PAR are disfavored in the presence of sexual antagonism.
染色体融合在基因组重排和核型进化中起着不可或缺的作用。将性染色体与常染色体融合的融合在整个生命之树上特别丰富。然而，以前关于建立这种融合的模型并没有考虑到染色体的物理结构。我们预测，将常染色体与性染色体的假常染色体区 (PAR) 融合的融合不会保持稳定，并且由于重组，融合将每代从 X 染色体切换到 Y 染色体。我们已经进行了正向时间群体遗传模拟，以探索融合到性染色体的 PAR 和非 PAR 区域的结果。该模型可以模拟含有性拮抗基因座的常染色体与性染色体的 PAR 或非 PAR 端的融合。我们的模型是二倍体、双基因座和双等位基因的。我们的结果显示出一种明显的模式，即在存在性拮抗的情况下，融合到非 PAR 区域是有利的，而在存在性拮抗的情况下，融合到 PAR 区域是不利的。
